import {toCanvas} from 'qrcode-lite'

import ReadOnly from './readonly'
import html from '../../templates/controls/qrcode'
import valueOrCall from '../utils/valueOrCall'

export default class QRCode extends ReadOnly
  tag: 'qrcode'
  html: html

  # pass this in optionally to overwrite a specific value
  text: ''

  # version '1' to '40', undefined for automatic detection (default)
  version: undefined

  # level of error correction
  # 'L' = 7%
  # 'M' = 15% (default)
  # 'Q' = 25%
  # 'H' = 35%
  # 'S' = 50% (unsupported)
  errorCorrectionLevel: 'M'

  # scale of a module
  scale: 4

  # margin of white area around qr code in pixels
  margin: 4

  events:
    updated: ->
      @onUpdated()
    mount: ->
      @onUpdated()

  init: ->
    super arguments...

  onUpdated: ->
    canvas = @root.children[0]
    toCanvas canvas, @getText(),
      version: parseInt @version, 10
      errorCorrectionLevel: @errorCorrectionLevel
      scale: parseInt @scale, 10
      margin: parseInt @margin, 10
    .catch (err)  ->
        console.error err

QRCode.register()